The New York Daily News reports hears MTV has warned Britney Spears to behave in Las Vegas or risk her spot on tonight’s Video Music Awards. “Britney knows she’s on thin ice,” said the tipster. “When they agreed to the performance, they sat her down and told her she should not be going out, and instead focus on rehearsing and resting. She seemed to be thankful and appreciative for the chance, but who knows with her? MTV made it clear that her usual behavior will not be tolerated.” Read more.